Pump with slotted cam



06L 4 1958 R. 1E. YAUGHER ETAL 5,

PUMP WITH SLOTTED CAM Filed March 14. 1956 INVENTOR-S.

Roaem' 5. YHUGHEZR MURRAY 6. McLsmv WARREN 0054.5

BY THE//? ATTORNEYS. Hake/s, mac, Fosrse a'Hnems United States Patent r 2,855,853 PUMP wrrn SLOTTED CAM Robert E. Yaugherand Murray G. McLean, Burbank, and Warren Doble, North Hollywood, Calif., assignors to Jabsco Pump Company, Burbank, Califi, a coipo- I ration of California Application March 14, 1956, Serial No. 571,539 7 Claims. (Cl. 103-117) vide a pump action, this type of pump being well known in the art.

For convenience in disclosing the present invention it will be considered herein as embodied in a flexible-bladed pump of the concentric type in which the required flexing of the blades is produced by a separate, nonintegral cam inserted into the housing. However, it will be undertood that the invention is not limited to this particular type of flexible-bladed pump and that it may be incorporated in flexible-bladed pumps of other types.

In a pump of the foregoing nature, fluid from the inle port is drawn into the interblade spaces as the blades straighten in moving along an inlet end portion or ramp of the cam adjacent the inlet port. Conversely, fluid is discharged from the interblade spaces into the outlet port as the blades bend in moving along an outlet end portion or ramp of' the cam adjacent the outlet port. In other words, it is necessary that the cam extend between the inlet and outlet ports and that the inlet and outlet ramps of the cam be located at the points where the inlet and outlet ports are located, thereby necessitating some means of flowing the fluid being pumped around or through the inlet and outlet ramps. The fluid being pumped could be caused to bypass these ramps bymaking the inlet and outlet ports axial ports communicating with the ends of the interblade spaces of the impeller, but this is undesirable for various reasons, and it is much more convenient tov utilize peripheral inlet and outlet ports communicating with the peripheries of the interblade spaces and to channel the fluid being pumped through openings in the cam ramps. Thus, the fluid entering the interblade spaces of the impeller from the inlet port flows through openings in the inlet ramp of the cam and the fluid discharged from the interblade spaces into the outlet port flows through openingsgin the outlet ramp thereof.

The openings in the ramps may be holes, or they may beperipherally extendingnotches or slots inthe ends of the cam. In either event, the openings must be small enough so that the blades do not enter them and become damaged. We have found that the best results are obtained with notches or slots extending peripherally from the ends of the cam toward the center thereof. Such notches or slots divide the end portions of the cam into axially spaced fingers or bars, the bars overlying the inlet port being engaged by the blades as they unbend to draw fluid into the interblade spaces from the inlet port, and the bars overlying the outlet port causing the .blades to bend to expel fluid from the interblade spaces into the outlet port.

In the past, such peripherally. extending bars overlying the inlet and outlet ports have caused'a great deal of trouble in intercepting solid matter in the fluid being pumped. Very frequently, the bars overlying the 'inlet port intercept enough solid matter to completely block the inlet port in a relatively short time. We have discovered that this trouble may beeliminated by extending the bars, and particularly the bars overlying the inlet port, only part way across the ports, and not more than about two-thirds of the way across the ports, this being a primary object of the invention.

With the foregoing construction, any foreign matter in the fluid being pumped can pass easily from the inlet port into the interblade spaces and from the interblade spaces into the outlet port. If, as will, be discussed in' more detail hereinafter, solid matter entering the inlet port tends to build up on the upstream sides of the inlet bars over the inlet port, it eventually is swept off the ends of the inlet bars so that it may enter one of the interblade spaces, which is an important feature of the invention. On the outlet side, solid matter can not build up ou-the upstream faces of the outlet bars because such solid matter is continuously swept away by the vanes and is ultimately discharged into the outlet port, which is another important Ieature.

The foregoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results thereof which will be apparent to those skilled in the art in the light of this disclosure, may be attained with the exemplary embodiment of the invention illustrated in the accompanying drawing and described in detail hereinafter. to the drawing:

Fig. 1 is a transverse sectional view of a pump which embodies the invention and illustrates the operation thereof when handling fibrous solid matter; and

Fig. 2 isa fragmentary isometric view of the pump of the invention and illustrates the operation thereof in handling crystalline solid matter.

Referring to the drawing, the numeral 10 designates a pump housing which is provided with a cylindrical impeller bore 12 andwhich is provided with circumferentially spaced, peripheral inlet and outlet ports 14 and 16 in the circumferential wall of the impeller bore. A shaft 18' extends into the impeller bore 12, the axis of the shaft coinciding with the axis of this bore. Keyed, or otherwise secured to the shaft 18 within the impeller bore 12, is an impeller 20 having flexible vanes or blades 22. Preferably, the entire impeller 20, including the hub thereof and the blades 22, is formed of a rubberlike material.

Disposed in the impeller bore 12 and shown as secured in place by a screw 24 is a cam 26, this cam extending between the inlet and outlet ports 14 and 16 and having inlet and outletend portions or ramps 23 and 34) respectively overlying the inlet and outlet ports 14 and 16. The inlet ramp 28 is provided with notches or slots 32 therein which extend peripherally from the extreme end of the cam toward the center thereof, the slots 32 dividing the inlet ramp 28 into axially spaced inlet bars or fingers 34'. Similarly, the outlet ramp 30 is provided with notches or slots 36 therein which extend peripherally from the extreme end of the cam 26 toward the center thereof and which divide the outlet ramp into a plurality Referring of axiallyspaced outlet fingers or bars 38.

As the impeller 20 rotates in the impeller chamber defined by the impeller bore 12 and the cam 26, the blades 22 alternately engage a section of the circumferential wall of the impeller bore and the inner wall of the cam, these forming the peripheral wall of the impeller chamber. The blades 22 are flexed by the cam 26, the blades straightening as they move along the inlet ramp 28 so that the interblade spaces enlarge and draw fluid from the inlet port 14 thereinto through the slots 32 in the inlet ramp. Conversely, as the blades 22 move along the outlet ramp 30, they are bent so that the interblade spaces contract to expel fluid therefrom through the slots 36 in the outlet ramp into the outlet port 16.

An imporant feature of the invention is that the inlet bars 34 extendonly part way across the inlet port 14 in the peripheral direction, and not more than about twothirds of the way thereacross. With this construction, it is impossible for solid matter in the fluid being pumped to hang up on the inlet bars 34 and thus obstruct flow from the inlet port 14 into the impeller chamber. Considering the case of fibrous matter entering the housing 10 through the inlet port 14, such fibrous matter may collect on the upstream sides of the inlet bars 34 tcmporarily, as indicated by the numeral 42. However, this fibrous material drapes around the inlet bars 34 so that it is engaged by and swept oil the inlet bars by the next blade 22, as indicated by the numeral 44, such fibrous material then entering one of the interblade spaces. Thus, fibrous material cannot collect on the inlet bars 34 in an amount sufficient to obstruct flow to any appreciable extent, the fibrous material continuously being swept off the ends of the inlet bars and into the interblade spaces by the blades 22, which is an important feature of the invention. In prior pumps of this nature wherein the inlet bars extend entirely across the inlet port, the blades cannot sweep solid matter off the ends of the inlet bars, with the result that solid matter builds up to such an extent as to block flow completely, this being avoided by the present invention.

Fig. 2 of the drawing illustrates how a crystal 46 aligns itself with the inlet end of the cam 26 so that it passes freely into one of the interblade spaces in parallel relation to the blades 22. If a crystal like the crystal 46 hangs up on the upstream surfaces of the inlet bars 34, an end thereof either projects into the impeller chamber between two of the inlet bars so that the crystal is swept ofi the ends of the inlet bars by one of the blades 22, or, if a crystal like the crystal 46 arrives in crosswise relation to the inlet bars and is momentarily arrested by the inlet bars in this crosswise position, the suction caused by the moving impeller blades moves the crystal to the ends of the bars so that it also may enter one of the interblade spaces in parallel relation with the blades.

Thus, it will be apparent that the present invention will handle solids of various types without having the solid matter pile up on the upstream sides of the inlet bars 34 to such an extent as to obstruct flow, the solid matter being constantly swept off the ends of the inlet bars.

The outlet bars 38 also extend not more than about two-thirds of the way across the outlet port 16 in the peripheraldirection so that solids may flow from the interblade spaces into the outlet port readily. If any solid matter does hang up on the upstream, i. e., inner, surfaces of the outlet bars 38, this solid matter is immediately swept away by the next blade 22 and is discharged the next time around.

Although we have disclosed specifically an exemplary embodiment of the invention,.it will be understood that various changes, modifications and substitutions may be incorporated in such embodiment without departing from the spirit of the invention as defined by the claims here inafter appearing.

We claim as our invention:

1. In a pump, the combination of: a housing providing an impeller chamber having an axis and providing peripheral inlet and outlet ports spaced apart along the peripheral wall of said impeller chamber, said peripheral wall including a cam section having a reduced radius relative to said axis and extending between said inlet and outlet ports and having peripherally spaced, inlet and outlet portions overlying said inlet and outlet ports, re spectively, said inlet and outlet portions being periph erally notched to provide fluid communication between said impeller chamber and said inlet and outlet ports, respectively, and to provide peripherally extending inlet and outlet bars overlying said inlet and outlet ports, respectively, said inlet bars extending only part way across said inlet port in one direction along said peripheral wall of said impeller chamber; and an impeller rotatable in said impeller chamber about said axis in said one direction and having flexible blades en gaging said peripheral wall thereof, said blades being flexed by said reduced-radius cam section when they engage same.

2. In a pump, the combination of: a housing providing an impeller chamber having an axis and providing peripheral inlet and outlet ports spaced apart along the peripheral wall of said impeller chamber, said peripheral wall including a cam section having a reduced radius relative to said axis and extending between said inlet and outlet ports and having peripherally spaced, inlet and outlet portions overlying said inlet and outlet ports, respec tively, said inlet and outlet portions being peripherally notched to provide fluid communication between said impeller chamber and said inlet and outlet ports, respectively, and to provide peripherally extending inlet and outlet bars overlying said inlet and outlet ports, respectively, said inlet bars extending only part Way across said inlet port in one direction along said peripheral wall of said impeller-chamber, and said outlet bars extending only part Way across said outlet port in the opposite direction along said peripheral wall of said impeller chamber; and an impeller rotatable in said impeller chamber about said axis in said one direction and having flexible blades engaging said peripheral wall thereof, said blades being flexed by said reduced-radius cam section when they engage same.

3. A pump according to claim 2 wherein said peripheral wall of said impeller chamber is defined partially by a section of the circumferential wall of a cylindrical impeller bore in said housing, the remainder of said peripheral wall, comprising said cam section thereof, being constituted by the inner side of a separate. arcuate cam disposed in said impeller bore and secured to said housing.

4. In a pump, the combination of: a housing provided with a cylindrical impeller bore therein having an axis and provided with circumferentially spaced inlet and outlet ports in the circumferential wall of said impeller bore; an arcuate cam disposed in said impeller bore and extending between said inlet and outlet ports, the inner side of said cam having a radius relative to said axis less than that of the circumferential wall of said impeller bore, and said cam having circumferentially spaced, inlet and outlet ramps overlying said inlet and outlet ports, respectively, said inlet and outlet ramps being circumferentially notched to provide fluid communication between said impeller bore and said inlet and outlet ports,-respectively, and to provide peripherally extending inlet and outlet bars overlying said inlet and outlet ports, respectively, saidinlet bars extending only part way across said inlet port in one circumferential direction; and an impeller rotatable in said impeller bore about said axis in said one circumferential direction and having flexible blades alternately engageable with the circumferential wall of said impeller bore and the inner side of said cam, said blades being flexed by said inner side of said cam when they engage same, and said blades being adapted to sweep olf said inlet bars any solid material intercepted thereby so that such solid material is carried into said impeller bore and into the interblade spaces of said impeller.

5. In a pump, the combination of: a housing provided with a cylindrical impeller bore therein having an axis and provided with circumferentially spaced inlet and outlet ports in the circumferential wall of said impeller bore; an arcuate cam disposed in said impeller bore and extending between said inlet and outlet ports, the inner side of said cam having a radius relative to said axis less than that of the circumferential wall of said impeller bore, and said cam having circumferentially spaced, inlet and outlet ramps overlying said inlet and outlet ports, respectively, said inlet and outlet ramps being circumferentiallynotehed to provide fluid communication between said impeller' bore and said inlet and outlet ports, respectively, and to provide peripherally extending inlet and outlet bars overlying said inlet and outlet ports, respectively, said inlet bars extending only part way across said inlet port in one circumferential direction, and said outlet bars extending only part way across said outlet port in the opposite circumferential direction; and an impeller rotatable in said impeller bore about said axis in said one circumferential direction and having flexible blades alternately engageable with the circumferential wall of said impeller bore and the inner side of said cam, said blades being flexed by said inner side of said cam when they engage same, and said blades being 7. In a pump, the combination of: a housing providing an impeller bore having an axis and providing peripheral inlet and outlet ports cireui ferentially spaced apart and of the circumferential wall of said impeller bore, and

said inlet and outlet portions being provided with openings therethrough, said inlet portion extending only part way across said inlet port in onecireumferential direction;

adapted to sweep off said, inlet and outlet bars any solid material intercepted thereby.

6. In a pump, the combination of: a housing providing an impeller chamber and providing a peripheral inlet port communicating with said impeller chamber; means providing axially spaced inlet bars overlying said inlet port and extending only part way across said inlet port in one peripheral direction; and an impeller rotatable in said impeller chamber in said one peripheral direction and having blades engageable with the inner surfaces of said inlet bars.

and an impeller rotatable in said impeller bore about said axis in said one circumferential direction and having I flexible blades alternately engageable with the circum ferential wall of said impeller bore and the inner surface of said cam, said blades being flexed by said inner side of said earn when they engage same. 7

References Cited in the file of this patent UNITED STATES PATENTS 861,626 Young July 30, 1907 2,052,474 Johnson Aug. 25, 1936 2,291,279 Jaworowski July 28, 1942 2,499,163 Rand Feb. 28, 1950 2,636,479 Smyser Apr. 28, 1953 2,663,263 Mayus et a1 Dec. 22, 1953 2,789,511 Doble Apr. 23, 1957 FOREIGN PATENTS 201,514 Australia Apr. 11, 1956 

